OpenTK
The Open Toolkit library is a fast, low-level C# wrapper for OpenGL
...OpenTK provides several utility libraries, including a math/linear algebra package, a windowing system, and input handling. OpenTK is not a game engine, nor does it try to be one: It offers a useful set of tools and lets you decide how to use them. It is the ideal starting point if you want to write a game or scientific application from the ground up. The OpenGL specification specifies exactly what the result/output of each function should be and how it should perform. It is then up to the developers implementing this specification to come up with a solution of how this function should operate. ...